Early Family Experiences and Neural Activity in Rural Pakistani Children: The Differential Role of Gender.

Adversity within low- and middle-income countries (LMICs) poses severe threats to neurocognitive development, which can be partially mitigated by high-quality early family experiences. Specifically, maternal scaffolding and home stimulation can buffer cognitive development in LMIC, possibly by protecting underlying neural functioning. However, the association between family experiences and neural activity remains largely unexplored in LMIC contexts. This study explored the relation of early family experiences to later cognitive skills and absolute gamma power (21-45 Hz), a neural marker linked to higher-order cognitive skills. Drawing data from the PEDS trial, a longitudinal study in rural Pakistan, we examined maternal scaffolding at 24 months and home stimulation quality at 18 months as predictors of verbal IQ, executive functions, and absolute gamma at 48 months for 105 mother-child dyads (52 girls). Maternal scaffolding interacted with gender to predict absolute gamma power, such that higher maternal scaffolding was related to higher gamma more strongly for girls. Maternal scaffolding also interacted with absolute gamma to predict executive functions, such that higher gamma was related to better executive functions only when maternal scaffolding was average to high. Individual differences in early family experiences may partially buffer the neural underpinnings of cognitive skills from adversity in LMIC.

Cortisol response marks biological sensitivity to kindergartners' social hierarchies for emerging school engagement.

This longitudinal study investigated how kindergartners' position in the classroom social hierarchy and cortisol response relate to their change in school engagement across the first year of kindergarten (N = 332, M = 5.3 years, 51% boys, 41% White, 18% Black). We used naturalistic classroom observations of social hierarchy positions, laboratory-based challenges to elicit salivary cortisol response, and teacher, parent, and child reports of emotional engagement with school. Robust, clustered regression models revealed that in the fall, lower cortisol response (but not social hierarchy position) was associated with greater school engagement. However, by spring, significant interactions emerged. Highly reactive, subordinate children showed increases in school engagement from fall to spring of the kindergarten year, whereas highly reactive, dominant children showed decreases in school engagement. This is some of the first evidence that higher cortisol response marks biological sensitivity to early peer-based social contexts.

The unique relevance of executive functions and self-regulation behaviors for understanding early childhood experiences and preschoolers' outcomes in rural Pakistan.

Performance-based measures of children's executive functions (EFs) do not capture children's application of these skills during everyday emotionally-laden and socially-mediated interactions. The current study demonstrates the value of using assessor report of self-regulation behaviors (inhibitory control and positive affect/engagement) in addition to EF tasks when studying early childhood experiences and development in a rural lower-middle-income country setting. In a sample of 1302 disadvantaged 4-year-olds living in rural Pakistan, we found that directly assessed EFs were significantly related to assessor observations of children's inhibitory control and positive affect/engagement during a structured assessment protocol. However, EFs and two types of self-regulation behaviors demonstrated unique associations with children's (1) contextual experiences, as indexed by family socio-economic resources, participation in parenting interventions, and children's physical growth; and (2) age-salient developmental outcomes, as indexed by direct assessment of pre-academic skills and maternal report of prosocial behaviors and behavior problems. First, family wealth uniquely predicted only observed positive affect/engagement, whereas maternal education uniquely predicted only EFs. Second, children's antecedent linear growth was a significant predictor of both EFs and positive affect/engagement, but exposure to an enhanced nutrition intervention during the first 2 years of life and preschoolers' hair cortisol concentration were associated only with observed self-regulation behaviors. Finally, both EFs and observed positive affect/engagement uniquely predicted children's pre-academic skills. In contrast, only assessors' ratings of positive affect/engagement uniquely predicted maternal report of prosocial behaviors and only assessors' ratings of inhibitory control uniquely predicted maternal report of behavioral problems.

Taking a few deep breaths significantly reduces children's physiological arousal in everyday settings: Results of a preregistered video intervention.

This preregistered, randomized field experiment tested the effectiveness of a brief deep breathing intervention on children's concurrent physiological arousal in naturalistic settings (N  = 342; Mage  = 7.48 years; 46% female; 53% Asian, 26% White; 21% other race/ethnicity). The treatment consisted of an animated video that introduced deep breathing as a self-regulation strategy and scaffolded the child in taking a few slow-paced breaths, while the control group watched an informational video featuring similar animated images. Respiratory sinus arrhythmia (RSA) and heart rate (HR) were measured while children were sitting still (baseline) and subsequently while watching 1-min videos. Relative to baseline arousal, RSA increased and HR decreased only in response to the deep-breathing treatment video. Effects were larger in the second 30-s epoch of the video, which included most of the deep breathing practice. RSA fully mediated the intervention's effects on HR. By analyzing all children exposed to intervention video regardless of their engagement in the deep breathing practice (intention-to-treat design) and by using easily scalable treatment videos, the study identifies an effective and pragmatic approach to reducing children's physiological arousal in everyday, group settings. Implications for advancing applied developmental psychophysiological research are discussed.

Parent-child physiological synchrony: Concurrent and lagged effects during dyadic laboratory interaction.

This study investigated whether parents and kindergarten children show concurrent and time-lagged physiological synchrony during dyadic interaction. Further, we tested whether parent-child behavioral co-regulation was associated with concurrent and time-lagged synchrony, and whether synchrony varied by the type of interaction task. Participants were 94 children (Mage  = 5.6 years, 56% female) and their parents. We simultaneously measured parent and child respiratory sinus arrhythmia (RSA) during four dyadic interaction tasks: free play, clean up, problem-solving, and puzzle teaching. We found that synchrony varied by task. Concurrent synchrony occurred only during the puzzle teaching task, such that parent and child RSA were significantly and positively associated with each other simultaneously. Time-lagged synchrony occurred only during the problem-solving task, such that parent RSA was positively associated with child RSA 30 seconds later, and child RSA was negatively associated with parent RSA 30 seconds later. Although behavioral co-regulation and physiological synchrony have been conceptualized as markers of responsive parent-child interactions, our study finds no evidence that physiological synchrony is associated with between-dyad differences in behavioral co-regulation.

Evaluating motor performance with the Bruininks-Oseretsky Test of motor proficiency in impoverished Pakistani children.

OBJECTIVE: To evaluate the sensitivity of the modified Brief Form of Bruininks Oseretsky Test in identifying motor differences secondary to malnutrition and poverty. METHODS: This longitudinal cohort study was conducted at Nowshero Feroze, Sindh from 2013 to 2014 and comprised data drawn from children who participated in a randomised controlled trial, that assessed responsive stimulation and nutrition interventions in the first two years of life. Outcome measures included motor development assessed using Brief Form of Bruininks Oseretsky Test, child anthropometry and household economic and demographic information. Data was analysed using SPSS 15 and STATA 12. RESULTS: Of the 1058 children, 570(53%) were boys. Moderate-severe stunting was reported in 171(16.12%) subjects, while moderate-severe underweight was reported in 117(11.1%). Also, 591(56%) subjects belonged to poor families, 343(32%) had illiterate mothers, and 392(37%) were food-insecure. Malnutrition, socio-economic status and maternal literacy were significantly associated with a 6-item motor composite of the Brief Form of Bruininks Oseretsky Test (p<0.05). CONCLUSIONS: The 6-item motor composite of the Brief Form of Bruininks Oseretsky Test was found to be a reliable tool to measure motor performance in Pakistani pre-school children.

Effects of small-sided games and high-intensity interval training on physical performance in young female handball players.

This study was designed to compare the effectiveness of small-sided handball games in combination with handball training (SSG group) versus high-intensity interval training in combination with handball training (HIIT group) on physical performance of young female handball players during pre-competitive period. Twenty-four young female handball players, who have a 6.17 ± 1.54 years training experience and competition in the national league participated in this study. SSG group (n = 12; age 16.06 ± 0.80 years, body mass 61.27 ± 3.68 kg, body height 1.64 ± 4.7 m, body mass index 22.7 kg/m2) while HIIT group (n = 12; 16.20 ± 1.28 years, body mass 62.46 ± 7.86 kg, body height 1.68 ± 6.8 m, body mass index 22 kg/m2). Both groups applied training programs twice-a-week for 8 weeks. Before and after the training programs physical performances were assessed: Countermovement jump (CMJ), Squat jump (SJ), Sprint on 0-10 m; Sprint on 0-20 m; Sprint on 0-30 m, Throwing medicine ball and total distance covered during the Yo-YoIRT1. After 8 weeks SSG and HIIT groups significantly improved CMJ, SJ, 0-20 m sprint, 0-30 m sprint, throwing medicine ball and Yo-YoIRT1 (p ≤ 0.05). However, significantly greater improvement was achieved in Yo-YoIRT1 (m) in HIIT group (28.40%) than SSG group (17.63%). These results indicate that SSG group and HIIT group equally improve of physical performances (jump, sprint and upper explosive strength) among young female handball players in pre-competitive period.

Addressing educational inequalities and promoting learning through studies of stress physiology in elementary school students.

To be ready to learn, children need to be focused, engaged, and able to bounce back from setbacks. However, many children come to school with heightened or diminished physiological arousal due to exposure to poverty-related risks. While stress physiology plays a role in explaining how adversity relates to processes that support students' cognitive development, there is a lack of studies of physiological stress response in educational settings. This review integrates relevant studies and offers future directions for research on the role of stress physiology in the school adaptation of elementary school students, focusing on these important questions: (a) What are the links between physiological stress response and learning-related skills and behaviors, and do they vary as a function of proximal and distal experiences outside of school? (b) How are school experiences associated with students' physiological stress response and related cognitive and behavioral adaptations? (c) How can we leverage measures of students' physiological stress response in evaluations of school-based interventions to better support the school success of every student? We hope to stimulate a new wave of research that will advance the science of developmental stress physiology, as well as improve the application of these findings in educational policy and practice.

Moving beyond executive functions: Challenge preference as a predictor of academic achievement in elementary school.

Intrinsic motivation and executive functions (EFs) have been independently studied as predictors of academic achievement in elementary school. The goal of this investigation was to understand how students' challenge preference (CP), an aspect of intrinsic motivation, is related to academic achievement while accounting for EFs as a confounding variable. Using data from a longitudinal study of 569 third-, fourth-, and fifth-graders (50% female), we tested students' self-reported CP as a predictor of mathematics and English language arts (ELA) achievement in multilevel models that controlled for school fixed effects and student demographic characteristics. CP was positively associated with mathematics and ELA over and above the set of covariates and EFs. While also controlling for prior achievement, CP continued to explain a small amount of unique variance in mathematics, but not in ELA. These results underscore the importance of including measures of students' intrinsic motivation, in addition to EFs, to obtain a comprehensive understanding of academic success.

Biological sensitivity to context in Pakistani preschoolers: Hair cortisol and family wealth are interactively associated with girls' cognitive skills.

Many young children in low- and middle-income countries (LMICs) face heightened risk for experiencing environmental adversity, which is linked with poorer developmental outcomes. Children's stress physiology can shed light on why children are differentially susceptible to adversity. However, no known studies have examined whether links between adversity and children's development are moderated by children's stress physiology in LMICs. The present study revealed significant interactive effects of hair cortisol concentrations, an index of chronic physiological stress regulation, and family wealth on preschoolers' cognitive skills in rural Pakistan. In a sample of 535 4-year-old children (n = 342 girls), we found significant associations between family wealth and direct assessments of verbal intelligence, pre-academic skills, and executive functions only in girls with lower hair cortisol concentrations. Specifically, girls with lower cortisol concentrations displayed greater cognitive skills if they came from relatively wealthier families, but lower cognitive skills if they came from very poor families. There were no significant associations among boys. Results provide evidence of biological sensitivity to context among young girls in a LMIC, perhaps reflecting, in part, sex differences in daily experiences of environmental adversity.

Introduction to special issue on global child development studies.

As global child development research is taking off, this special issue provides a collection of recent research characterizing child development across the globe, validating behavioral and neuroimaging tools across diverse geographical setting and cultures, exploring relationships between risk and protective factors and diverse child outcomes, and testing novel avenues of innovative intervention. In particular, three prominent themes that emerge from this special issue are (a) research linking biology and behavior in the service of uncovering biological systems that are susceptible to experience and may mediate associations between experiences and long-term developmental outcomes in global child development research, (b) a movement towards inclusion of more detailed investigation of children's socio-emotional functions in global child development research, and (c) longitudinal studies of developmental outcomes across global settings. In this introduction we outline key themes and findings from the 25 articles included in the special issue.

Early executive functioning in a global context: Developmental continuity and family protective factors.

This study extends the methodological and theoretical understanding of executive functions (EFs) in preschoolers from low- and middle-income countries (LMIC). First, the authors describe a rigorous process of adapting and evaluating six EF tasks to produce a culturally and developmentally appropriate measure of emerging EFs in a large sample of at-risk children in rural Pakistan. Next, the authors identify critical developmental and family factors that relate to preschoolers' EFs over the first 4 years of life. Direct assessment of children's general cognitive skills at age two showed developmental continuity with EFs at age four, and these early cognitive skills mediated the effect of an antecedent parenting intervention on EFs as well as associations of targeted individual and family factors with EFs. Furthermore, directly assessed maternal cognitive capacities and observed maternal scaffolding uniquely predicted EFs in preschoolers. This study is also the first to demonstrate a significant overlap between direct assessments of IQ and EFs in young children from LMIC. Children's general intelligence mediated the associations of EFs with antecedent physical growth and cognitive skills as well as concurrent family factors (maternal verbal intelligence, maternal scaffolding, and home stimulation). After controlling for shared variance between preschoolers' general intelligence and EFs, three factors emerged as unique predictors of EFs: exposure to an early parenting intervention, physical growth status at age two, and number of older siblings. The findings have important implications for the design of interventions that aim to improve EFs in young children in LMIC. A video abstract of this article can be viewed at https://vimeo.com/316329544/5abde94cd7.

Teachers' rankings of children's executive functions: Validating a methodology for school-based data collection.

We developed a novel, vignette-based ranking procedure to simultaneously collect teacher-reported executive function (EF) data for all students in a classroom. This ranking measure is an improvement over existing Likert-type rating scales because it can be completed more quickly and with comparatively little effort by teachers. Data for this validation study were drawn from a large, school-based study of third, fourth, and fifth graders (N = 813 from 33 classrooms in eight schools) in which ranking data and direct assessments of EF were collected. Using a subsample of students for whom teachers' ratings of EF and school records data were also collected (N = 311), we demonstrated that teachers' rankings of EF showed high convergent validity with teachers' ratings of EF and that both teacher-reported measures showed similar convergent validity with direct assessments of EF and similar predictive validity with respect to students' scores on standardized English/language arts and math achievement tests. Using data from the larger sample (N = 813), we conducted a simulation study demonstrating that the impact of missing data on the association between the rankings and the direct assessments of EF is minimal. Based on these results, the ranking procedure is a methodological innovation that enables the collection of relatively high-quality teacher-reported EF data for all students in a classroom quickly and with minimal burden on teachers. This vignette-based assessment method could be adapted to other domains of non-academic skills. We discuss varied uses of the ranking method for researchers and practitioners.

Linking executive function skills and physiological challenge response: Piecewise growth curve modeling.

This study employed piecewise growth curve modeling to examine how children's executive function (EF) skills relate to different components of children's physiological response trajectory - initial arousal, reactivity, and recovery. The sample included 102 ethnically diverse kindergarteners, whose EF skills were measured using standard tasks and observer ratings. Physiological response was measured via changes in respiratory sinus arrhythmia (RSA) in response to a laboratory socio-cognitive challenge. Children's cool and hot EF skills were differentially related to both linear and quadratic components of RSA response during the challenge. Greater hot EF skills and assessor report of EF skills during laboratory visit were related to quicker RSA recovery after the challenge. These findings demonstrate that children's physiological response is a dynamic process that encompasses physiological recovery and relates to children's self-regulation abilities.

Biological Sensitivity to Family Income: Differential Effects on Early Executive Functioning.

The study examined how the interplay between children's cortisol response and family income is related to executive function (EF) skills. The sample included one hundred and two 5- to 6-year-olds (64% minority). EF skills were measured using laboratory tasks and observer ratings. Physiological reactivity was assessed via cortisol response during a laboratory visit. A consistent, positive association between family income and EF skills emerged only for children who showed high cortisol response, a marker of biological sensitivity to context. In contrast, family income was not related to EF skills in children who displayed low cortisol response. Follow-up analyses revealed a disordinal interaction, suggesting that differential susceptibility can be detected at the level of basic cognitive and self-regulatory skills that support adaptive functioning.

Social stratification, classroom climate, and the behavioral adaptation of kindergarten children.

Socioeconomic status (SES) is the single most potent determinant of health within human populations, from infancy through old age. Although the social stratification of health is nearly universal, there is persistent uncertainty regarding the dimensions of SES that effect such inequalities and thus little clarity about the principles of intervention by which inequalities might be abated. Guided by animal models of hierarchical organization and the health correlates of subordination, this prospective study examined the partitioning of children's adaptive behavioral development by their positions within kindergarten classroom hierarchies. A sample of 338 5-y-old children was recruited from 29 Berkeley, California public school classrooms. A naturalistic observational measure of social position, parent-reported family SES, and child-reported classroom climate were used in estimating multilevel, random-effects models of children's adaptive behavior at the end of the kindergarten year. Children occupying subordinate positions had significantly more maladaptive behavioral outcomes than their dominant peers. Further, interaction terms revealed that low family SES and female sex magnified, and teachers' child-centered pedagogical practices diminished, the adverse influences of social subordination. Taken together, results suggest that, even within early childhood groups, social stratification is associated with a partitioning of adaptive behavioral outcomes and that the character of larger societal and school structures in which such groups are nested can moderate rank-behavior associations.

Effects of Neuromuscular Electrical Stimulation and Resistance Training on Knee Extensor/Flexor Muscles.

Neuromuscular electrical stimulation (NMES) has recently drawn a lot of attention as means for strengthening of voluntary muscle contraction both in sport and rehabilitation. NMES training increases maximal voluntary contraction (MVC) force output through neural adaptations. On the other hand, positive effects of resistance training (RT) on muscle strength are well known. The aim of this study was to investigate effects of a 5-week program of NMES compared to RT program of same duration. Sample of 15 students' of faculty of sport and physical education (age 22 ± 2) were randomized in two groups: NMES (N = 7) and RT (N = 8). NMES group performed NMES superimposed over voluntary muscle contraction, RT group performed resistance training with submaximal loads. Subjects were evaluated for knee isokinetic dynamometry on both sides (60° and 180° s). After intervention no significant difference between groups were observed in isokinetic dynamometry (p = 0.177). However, applying pair sample t test within each group revealed that peak torque increased in NMES-group (p = 0.002 for right knee extensors muscles, p = 0.003 for left, respectively, at 60° and p = 0.004 for left knee extensors muscles, at angular velocity 180°). In RT group (p = 0.033 for right knee extensors muscles, p = 0.029 for right knee flexor muscles, at angular velocity 60°). Our results indicate that NMES has equal potential if not in some way better than classical RT having in mind that overload on locomotor apparatus during NMES is minimal and force of muscle contraction is equal on both sides, for enhancement of knee muscles concentric peak torque.

An integrative view of school functioning: transactions between self-regulation, school engagement, and teacher-child relationship quality.

This study investigates the dynamic interplay between teacher-child relationship quality and children's behaviors across kindergarten and first grade to predict academic competence in first grade. Using a sample of 338 ethnically diverse 5-year-old children, nested path analytic models were conducted to examine bidirectional pathways between children's behaviors and teacher-child relationship quality. Low self-regulation in kindergarten fall, as indexed by inattention and impulsive behaviors, predicted more conflict with teachers in kindergarten spring and this effect persisted into first grade. Conflict and low self-regulation jointly predicted decreases in school engagement which in turn predicted first-grade academic competence. Findings illustrate the importance of considering transactions between self-regulation, teacher-child relationship quality, and school engagement in predicting academic competence.

The symphonic structure of childhood stress reactivity: patterns of sympathetic, parasympathetic, and adrenocortical responses to psychological challenge.

Despite widespread recognition that the physiological systems underlying stress reactivity are well coordinated at a neurobiological level, surprisingly little empirical attention has been given to delineating precisely how the systems actually interact with one another when confronted with stress. We examined cross-system response proclivities in anticipation of and following standardized laboratory challenges in 664 4- to 14-year-olds from four independent studies. In each study, measures of stress reactivity within both the locus coeruleus-norepinephrine system (i.e., the sympathetic and parasympathetic branches of the autonomic nervous system) and the corticotrophin releasing hormone system (i.e., the hypothalamic-pituitary-adrenal axis) were collected. Latent profile analyses revealed six distinctive patterns that recurred across the samples: moderate reactivity (average cross-system activation; 52%-80% of children across samples), parasympathetic-specific reactivity (2%-36%), anticipatory arousal (4%-9%), multisystem reactivity (7%-14%), hypothalamic-pituitary-adrenal axis specific reactivity (6%-7%), and underarousal (0%-2%). Groups meaningfully differed in socioeconomic status, family adversity, and age. Results highlight the sample-level reliability of children's neuroendocrine responses to stress and suggest important cross-system regularities that are linked to development and prior experiences and may have implications for subsequent physical and mental morbidity.

Principles for Adapting Assessments of Executive Function across Cultural Contexts.

Direct assessments of executive functions (EFs) are increasingly used in research and clinical settings, with a central assumption that they assess "universal" underlying skills. Their use is spreading globally, raising questions about the cultural appropriateness of assessments devised in Western industrialized countries. We selectively reviewed multidisciplinary evidence and theory to identify sets of cultural preferences that may be at odds with the implicit assumptions of EF assessments. These preferences relate to motivation and compliance; cultural expectations for interpersonal engagement; contextualized vs. academic thinking; cultural notions of speed and time; the willingness to be silly, be incorrect, or do the opposite; and subject-matter familiarity. In each case, we discuss how the cultural preference may be incompatible with the assumptions of assessments, and how future research and practice can address the issue. Many of the cultural preferences discussed differ between interdependent and independent cultures and between schooled and unschooled populations. Adapting testing protocols to these cultural preferences in different contexts will be important for expanding our scientific understanding of EF from the narrow slice of the human population that has participated in the research to date.